Methods and systems for heart valve therapy

ABSTRACT

Systems and methods for medical interventional procedures, including approaches to valve implantation. In one aspect, the methods and systems involve a modular approach to mitral valve therapy.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims the benefit of U.S. Application Ser. No.61/894,766, filed Oct. 23, 2013, the entire disclosure of which isexpressly incorporated herein.

BACKGROUND OF THE DISCLOSURE

The present disclosure relates to heart valve interventional systems andmethods and more particularly, to mitral valve therapy systems andmethods.

The long-term clinical effect of valve regurgitation is well recognizedas a significant contributor to cardiovascular related morbidity andmortality. Thus, the primary goal of any therapy of the mitral valve isto significantly reduce or eliminate the regurgitation. By eliminatingthe regurgitation, the destructive volume overload effects on the leftventricle are attenuated. The volume overload of mitral regurgitation(MR) relates to the excessive kinetic energy required during isotoniccontraction to generate overall stroke volume in an attempt to maintainforward stroke volume and cardiac output. It also relates to thepressure potential energy dissipation of the leaking valve during themost energy-consuming portion of the cardiac cycle, isovolumiccontraction. Additionally, successful MR reduction should have theeffect of reducing the elevated pressures in the left atrium andpulmonary vasculature reducing pulmonary edema (congestion) andshortness of breath symptomatology. It also has a positive effect on thefilling profile of the left ventricle (LV) and the restrictive LVphysiology that can result with MR. These pathophysiologic issuesindicate the potential benefits of MR therapy, but also indicates thecomplexity of the system and the need for a therapy to focus beyond theMR level or grade.

It is also desirable to prevent new deleterious physiology or functionof the valve. The procedure and system used to fix the mitral valveideally should avoid worsening other (non-MR) existing pathologicconditions or creating new pathologic conditions as a result of thetreatment. One of the critical factors to be managed is mitral stenosisor creation of an inflow gradient. That is, if a valve system is usedthat does not allow for sufficient LV inflow without elevated fillingpressures, then critical benefits of MR reduction are dissipated orlost. Moreover, atrial fibrillation is to be avoided as it can result ifelevated pressures are not relieved by the therapy, or are created bythe system (high pressure results in atrial stress leading to dilatationultimately leading to arrhythmias). Also, if the procedure results indamage to atrial tissue at surgery, it can result in the negativephysiologic effect of atrial fibrillation. Further, one should be awareof the possibility of increased LV wall stress through an increase in LVsize (LV geometry). Due to the integral relationship of the mitral valvewith LV geometry through the papillary and chordal apparatus, LV wallstress levels can be directly affected resulting in alterations of LVfilling and contraction mechanics. Accordingly, a system that does notpreserve or worsens the geometry of the LV can counter the benefits ofMR reduction because of the alteration of contractile physiology.

It has been generally agreed that it is preferable if the native valvecan be repaired (e.g. with an annular ring), versus an open surgicalvalve replacement. Repair of valve elements that target the regurgitantjet only results in minimal alteration to the valve elements/structuresthat are properly functioning allowing for the least potential fornegatively affecting the overall physiology while achieving the primarygoal. Native valve preservation can be beneficial because a wellrepaired valve is considered to have a better chance of having longstanding durability versus a replacement with an artificial valve thathas durability limits. Also, while current surgical artificial valvesattempt chord sparing procedures, the LV geometric relationship may benegatively altered if not performed or performed poorly leading to anincrease in LV wall stress due to an increase in LV diameter. Thus,while repair is preferred and possible for technically competentsurgeons, the relatively high recurrence rate of MR due to inadequaterepair, the invasiveness of the surgery especially in sick or functionalMR patients, and the complexities of a repair for many surgeons lead toa high percentage of mitral operations being replacement.

Conventionally, surgical repair or replacement of the mitral valve isperformed on cardiopulmonary bypass and is usually performed via an openmedian sternotomy resulting in one of the most invasive high riskcardiac surgical operations performed, especially in subpopulations suchas functional MR. Therefore, a key improvement to mitral valveoperations is to significantly lower the risk and invasiveness,specifically utilizing a percutaneous or minimally invasive technique.

While there have been attempts to replicate existing surgical repair vialess invasive surgical or percutaneous methods, given the complexity ofrepairing the valve surgically, the efforts have largely been deemedlacking in achieving adequate efficacy and have not altered the riskbenefit ratio sufficiently to warrant ongoing investment, approval, oradoption. In particular, there has been a general technology failure dueto the complexity of anatomy to percutaneously manage with an implant orimplantable procedure. The broad spectrum of mitral disease directlyinfluences outcomes with a resulting inability to match technology withpathology. There has also been observed inadequate efficacy with poorsurgical replication and safety results. It has also been recognizedthat percutaneous approaches have been successful to certain valveprocedures, such as aortic valve replacement associated with a singlepathology and a relatively circular rigid substrate, mitral valves oftensuffer from multiple pathologies and a have flexible or elastic annuluswith multiple structures, making this a more challenging goal.

Further challenges exist in positioning and orienting mitralregurgitation therapy structures at the interventional site. Cooperationand sealing between component parts has also been a consideration ineffective mitral regurgitation therapy. Additionally, more can be doneto both identify and take advantage of native anatomical features commonto the mitral valve. More can also be done to streamline theimplantation process.

Accordingly, what is needed is an effective long lasting MR reductionwithout creating negative physiologic consequences to thecardio-pulmonary system (heart, lungs, peripheral vasculature) includingstenosis, LV wall stress and atrial fibrillation. It is also desirableto be able to perform the operation in a reliable, repeatable, and easyto perform procedure and to have a broadly applicable procedure for bothpatients and physicians, while employing a significantly less invasivemethod. Moreover, it is desirable to take advantage of anatomicalfeatures leading themselves to an effective mitral regurgitationtherapy, and to provide component structures which cooperate to addressregurgitation as well as implantation aids facilitating properorientation and placement.

The present disclosure addresses these and other needs.

SUMMARY

Briefly and in general terms, the present disclosure is directed towardsreplacement systems and methods. In one particular aspect, the presentdisclosure describes a percutaneous or minimally invasive mitral valvereplacement system that eliminates MR, provides adequate physiologicinflow, and preserves and/or improves LV geometry in a reliable,repeatable, and easy to perform procedure.

In one aspect, there is provided a mitral valve replacement systemincluding an anchoring structure and an artificial valve configured totreat a native heart. In another aspect, there is provided a method ofreplacing a valve including providing anchor structure, advancing avalve delivery catheter into a heart, advancing an artificial valve outof the delivery catheter and into the heart, and positioning theartificial valve to treat a native heart.

An anchor assembly configured with feet or projections sized and shapedto engage an anatomical gutter located in the left ventricle proximatethe mitral valve annulus acts as support for subsequent implantation ofa replacement valve assembly. An orientation and location tool can beemployed to facilitate proper positioning of the anchor assembly andreplacement valve assembly at the mitral valve interventional site. Inthis regard, remote visualization techniques can be set in response tomarkers provided on the orientation tool and subsequently employedduring an implantation procedure. An anchor placement tool orsub-structure is further provided to gain access to the mitral valve ina minimally invasive manner. Delivery systems for the anchor and valveassemblies likewise accomplish non-traumatic implantation. The anchorassembly includes structure for placement at or proximate a mitral valveannulus, as well as structure for sealing within anatomy and engagementwith a waist portion of the mitral valve assembly. The implanted mitralvalve presents a tri-leaflet structure for controlling blood flow, aswell as structure for accomplishing a seal within the anchor.

In certain approaches, forces can be translated to various anatomicalfeatures of and proximate the mitral valve. In one approach, an anchorassembly can be implanted within the anatomical gutter leaving theleaflets of the mitral valve unaffected. In other approaches, structureof the anchor can cross the annulus of the mitral valve and can furtherpartially or completely retain leaflets. Thus, forces generated by theheart and inherent in blood flow can be translated by an anchor directlyand solely to the anatomical gutter, or such forces can be in parttranslated to leaflet, chordae and papillary muscle anatomy to varyingdegrees.

In one approach, the mitral valve replacement system addresses a numberof basic functional requirements. One requirement is the valve functionitself, the occlusion of flow during systole, and open to flow duringdiastole. Another requirement is the seal between the artificialreplacement valve frame/structure and the tissue to prevent/minimize anyparavalvular leaks or flow. A further requirement is the anchoring orsecurement function to hold the functioning valve in position andwithstand the substantial and variable cyclical load placed on the valveduring systolic pressurization of the valve surface. It is intended thateach of these is met in the durable, therapeutically, andphysiologically appropriate mitral valve replacement system disclosedherein.

The presently disclosed system may utilize a staged approach to thefunctional elements of the system, starting with the anchoring orsecurement functional element. Additionally, the staging can beperformed within a single procedure or in multiple, time separatedprocedures, e.g. on different days. By staging and separating functionalelements, the individual elements will be simpler in design and simplerto deploy and implant. This staging of the anchor implantation of thepresent invention provides a stable, reliable, consistent, substrate todeliver a replacement valve into the mitral position.

A mitral valve treatment system according to the present disclosureincludes one or more of an anchor element, a sealing element, and avalve element, and can utilize an anchor delivery system, and a valvedelivery system. More than one element may be incorporated into astructure, for example, an anchor element also may include a sealingstructure, or a valve element may include a sealing structure. Inaccordance with the present teachings, the elements of the valvereplacement system may be implanted in staged procedures, for example,an anchor element may be implanted during a first procedure and a valveelement may be implanted during a second procedure. As disclosed herein,the processes, systems used for implantation, and timing of implantationmay vary. The present disclosure further contemplates that the anchorelement (and in some cases sealing element) of the disclosed mitralvalve replacement system may be used with existing valve technologies,as discussed further below. Similarly, delivery systems may includethose disclosed herein, but the present disclosure also contemplatesthat existing delivery systems may be used to deliver prior art valvestructures.

Moreover, the valve anchor approach can fundamentally alter thecomplexity of performing a completely percutaneous mitral replacement bycreating a reliable and consistent substrate. Thus, it is intended thatthe implant design exploit the geometry/mechanics of the commissures tocreate sufficient holding capability. In one particular aspect, asstated, the anatomical gutter found below a valve annulus is the sitefor anchoring. Further, design and delivery approaches that maintainnative valve function providing the ability to completely separate andstage the implantation of the system functional components iscontemplated as are delivery methods that have potential for quickfluoroscopic delivery, positioning, and deployment. Consequently, thereis an optimal valve performance opportunity due to maximal designflexibility and technology leveraging, and a delivery capability toachieve precise positioning prior to valve deployment. The same createsdesired tissue/implant sealing and maintains sub-valvular structuralrelationships.

Accordingly, employing the present system and method facilitateseffective long lasting MR reduction without creating negativephysiologic consequences to the cardio-pulmonary system (heart, lungs,peripheral vasculature) including stenosis, LV wall stress, and atrialfibrillation. The method can involve performance of the operation in areliable, repeatable, and easy to perform procedure and is a broadlyapplicable procedure for both patients and physicians. A significantlyless invasive method results, one which can be fully percutaneous fromthe start.

Other features and advantages of the present disclosure will becomeapparent from the following detailed description, taken in conjunctionwith the accompanying drawings, which illustrate, by way of example, theprinciples of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view, depicting a native heart indicating anoperating window region;

FIG. 2 is a top view, depicting a gutter perimeter of a valve includingidentified anchor locations;

FIG. 3 is a CT sectional view of gutter anatomy, depicting leaflets andleft ventricle wall with anchor locations identified;

FIG. 4 is a sub-valvular view, depicting an anatomical gutter perimeterwith anchor locations identified;

FIG. 5 is a side cross-sectional view, depicting tissue interfaces andan anatomical gutter with a leaflet closed;

FIG. 6 is a side cross-sectional view, depicting tissue interfaces andanatomical gutter with a leaflet open;

FIG. 7 is a lateral view, depicting a leaflet, subanular area behind theleaflet and a chordal web;

FIG. 8 is a rotated view, depicting an anchor foot passing throughanatomy;

FIG. 9 is a perspective view, depicting a chordal tent with planarseparation;

FIG. 10 is a perspective view, depicting loop structure passing througha coaptive margin;

FIG. 11 is a side cross-sectional view, depicting tissue interfaces;

FIG. 12 is a side cross-sectional view, depicting leaflet tip loading;

FIG. 13 is a side cross-sectional view, depicting alternative leafletbody loading;

FIG. 14 is a side cross-sectional view, depicting annulus loading;

FIG. 15A is a side cross-sectional view, depicting anchor structure anda closed leaflet;

FIG. 15B is a side cross-sectional view, depicting anchor structure witha leaflet open;

FIG. 16 is a side view, depicting one embodiment of a wire frame anchorstructure;

FIG. 17 is a side view of the structure of FIG. 16 with Dacron coveringremoved;

FIG. 18 is a top view, depicting the wire frame of FIG. 16;

FIG. 19 is a top view, depicting the wire frame of FIG. 18 with a Dacroncover removed;

FIG. 20 is a side view of the anchor, depicting the valve assemblyloaded within the anchor structure of FIG. 16;

FIG. 21 is a fluoroscopic image, showing an anchor and valve implantedwithin anatomy;

FIG. 22 is a top view, depicting a laser cut ribbon frame anchor;

FIG. 23 is a perspective view, depicting the laser cut ribbon frameanchor of FIG. 22;

FIG. 24 is a top anatomic view, depicting an anchor with forwardprojecting commissural projections or feet;

FIG. 25 is a side view, depicting the anchor of FIG. 24;

FIG. 26 is a side cross-sectional view, depicting clip structure of ananchor configured within anatomy;

FIG. 27 is a top view, depicting an anchor with clip structure placedabout an open valve;

FIG. 28 is a top view, depicting the anchor structure of FIG. 27 placedabout a closed valve;

FIG. 29 is a perspective view, depicting the anchor of FIGS. 24 and 25;

FIG. 30 is a side view, depicting a valve frame;

FIG. 31 is a side view, depicting the valve frame of FIG. 30 with acovering;

FIG. 32 is a top view, depicting the valve frame of FIG. 30;

FIG. 33 is a top view, depicting the valve frame of FIG. 31 placedwithin simulated anatomy;

FIG. 34 is a bottom view, depicting the valve of FIG. 31 placed withinsimulated anatomy;

FIG. 35 is a perspective view, depicting another approach to a wireframe for a valve assembly;

FIG. 36 is a side view, depicting the wire frame of FIG. 35;

FIG. 37 is a bottom view, depicting a covered valve frame in a closedposition;

FIG. 38 is a bottom view, depicting the valve frame of FIG. 37 in anopen position;

FIG. 39 is a fluoroscopic side view, depicting the valve of FIG. 31placed within tissue;

FIG. 40 is a cross-sectional side view, depicting a sealing skirt of avalve assembly;

FIG. 40A is a cross-sectional top view, depicting a sealing skirt of avalve assembly;

FIG. 41 is a perspective view, depicting heart anatomy and desiredimaging planes;

FIG. 42 is a perspective view, depicting an orientation tool;

FIG. 43 is a side view, depicting the orientation tool of FIG. 42;

FIG. 44 is a schematic representation of an echo image, depicting use ofan orientation tool within anatomy;

FIG. 45 is a fluoroscopic side view, depicting further use of anorientation tool within anatomy;

FIG. 46 is a fluoroscopic side view, depicting yet further use of theorientation tool within anatomy;

FIG. 47 is a perspective view, depicting an alternative approach to anorientation tool;

FIG. 48 is a perspective view, depicting further details of theorientation loop of FIG. 42;

FIG. 49 is a back view, depicting the orientation tube of FIG. 48;

FIG. 50 is a side view, depicting the orientation tool of FIG. 48;

FIG. 51 is a side view, depicting further details of the orientationtool of FIG. 49;

FIG. 52 is a rotated side view, depicting yet further details of theorientation tool of FIG. 50;

FIG. 53A is a top view, depicting use of the orientation tool;

FIG. 53B is an enlarged view, depicting markers;

FIG. 53C is an enlarged view, depicting rotationally aligned markers;

FIG. 53D is a perspective view, depicting a cylindrical shaft which isnot aligned with an imaging plane;

FIG. 53E is a side view, depicting a cylindrical shaft which is in planeor parallel with an imaging plane;

FIG. 54 is a side view, depicting positioning frame structure;

FIG. 55 is a rotated side view, depicting the positioning framestructure of FIG. 54;

FIG. 56 is a top view, depicting the positioning frame of FIG. 54;

FIG. 57 is a perspective view, depicting the positioning frame structurewithin anatomy;

FIG. 58 is a side view, depicting further use of the positioning framestructure within anatomy;

FIG. 59 is a cross-sectional view, depicting positioning of a leftatrial access catheter;

FIG. 60 is a top cross-sectional view, depicting a left atrial accesscatheter within anatomy;

FIG. 61 is a side view, depicting one embodiment of a delivery system;

FIG. 62 is a side view, depicting an outer sheath of the delivery systemdepicted in FIG. 61;

FIG. 63 is a side view, depicting a delivery sheath of the deliverysystem of FIG. 61;

FIG. 64 is a side view, depicting an inner assembly of the deliverysystem of FIG. 61;

FIG. 65 is a perspective view, depicting advancing a delivery systemtowards a mitral valve plane;

FIG. 66 is a perspective view, depicting a partially expressed anchor ofa delivery system;

FIG. 67 is a perspective view, depicting further expression of an anchorassembly;

FIG. 68 is a perspective view, depicting further advancement of ananchor and delivery sheath through simulated anatomy;

FIG. 69 is a perspective view, depicting yet further expression of ananchor within simulated anatomy;

FIG. 70 is a perspective view, depicting placement of anchor structurewithin simulated anatomy;

FIG. 71 is a side view, depicting recapturing an anchor assembly;

FIG. 72 is a side view partially in cross-section, depicting oneembodiment of a valve delivery catheter;

FIG. 73 is a side view depicting one approach to an articulation of adelivery catheter;

FIG. 74 is a side view, depicting another approach to an articulatingportion of a catheter;

FIG. 75 is a side view partially in cross-section, depicting a distalportion of a valve delivery catheter;

FIG. 76 is a perspective view of a distal end of a delivery catheter;

FIG. 77 is a side view depicting a helical structure of a deliverycatheter;

FIG. 78A-F are various views, depicting a distal portion of a valvedelivery catheter;

FIG. 79 is a perspective view, depicting a cone structure forincorporation into a delivery catheter;

FIG. 80 is a perspective view, depicting a valve delivery sheathcatheter;

FIG. 81 is a side view with portions in cross section, depicting detailsof a capsule pullback mechanism;

FIG. 82 is a side view, depicting the structure of FIG. 81 with a curveddistal section;

FIG. 83 is a perspective view, depicting a distal capsule and sleeveinstruction;

FIG. 83A is a fluoroscopic view of a valve prior to expansion into theanchor;

FIG. 84 is a perspective view, depicting a deflectable tip catheterstructure;

FIG. 85 is a perspective view, depicting another embodiment of adeflectable tip catheter within anatomy;

FIG. 86 is a side view, depicting a deflectable tip catheter with twodeflection points;

FIG. 87 is a side view, depicting a rotated view of the structuredepicted in FIG. 86;

FIG. 88 is a side view, depicting another approach to a deflectable tipcatheter with two deflection points; and

FIG. 89 is a rotated view, depicting the deflectable tip catheter ofFIG. 88.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, which are provided by way of backgroundand example, and not limitation, the present disclosure relates tomedical interventional procedures and devices. In various aspects, heartvalve therapy is addressed and in particular, mitral valve replacementapproaches are presented.

Overall, the present disclosure describes a system including a platformanchor, valve, and delivery technology that allows therapeuticflexibility (mitral replacement with either tissue or mechanicalvalves), implantation flexibility via either fully percutaneous orminimally invasive (trans-apical, trans-atrial) procedures, minimizeddelivery complexity to allow a simple to perform procedure, and apatient population that is not restricted by the underlying pathology.

A mitral valve replacement system according to the present disclosureincludes one or more of an anchor element, sealing structure, and avalve element, and utilizes orientation tools as well as an anchordelivery system, and a valve delivery system. An anatomical gutterproximate the mitral valve is intended to be a target for anchoring atleast portions of the replacement system. Generally, the gutter is athree dimensional composite LV sided anatomic structure that extends ina u-shape from one trigone region to the other bounded by the mitralleaflets on one side, annulus in the base region of the gutter, and theLV wall on the other side. Functionally, it collects and divertssub-annular/leaflet blood during systole into the aortic outflow tract.

More than one element may be incorporated into a structure, for example,an anchor element also may include a sealing structure, or a valveelement may include a sealing structure. In accordance with the presentteachings, the elements of the valve replacement system may be implantedin staged procedures, for example, an anchor element may be implantedduring a first procedure and a valve element may be implanted during asecond procedure. As disclosed herein, the processes, systems used forimplantation, and timing of implantation may vary. The presentdisclosure further contemplates that the anchor element (and in somecases sealing element) of the disclosed mitral valve replacement systemmay be used with existing valve structures, as discussed further below.Similarly, delivery systems may include those disclosed herein, but thepresent disclosure also contemplates that existing delivery systems maybe used to deliver prior art valve structures.

It should be noted that in planned percutaneous structural heartinterventions (TAVI, mitral repair, mitral replacement) (i.e.percutaneous), there are typically at least two procedures performed foreach individual patient. The first procedure includes a diagnosticassessment and possible PCI/stenting of the patient's coronary arteriesand often includes a right heart cath for cardiac physiology assessment.Valve implantation and or repair are not performed prior to knowing thepatient has been previously completely revascularized if necessary.

Generally the most difficult and most significant requirement for a lessinvasive valve system is the anchoring attachment of the system. Thepresently disclosed mitral valve replacement system staging of theanchor implantation allows exploitation of various anatomic valve andventricular structures to achieve the required holding force of theanchor system. When performed in two time separated procedures, stagingthe implantation of the anchor separately from other system elementsprovides time for tissue ingrowth into the anchor structure andresultant strengthening of the overall holding force of the anchorstructure in the anatomy.

Staging of anchor implantation allows for maintaining native valvefunction until artificial valve element(s) are in place. Staging alsohelps in mitral valve replacement where there is limited operatingspace. It is to be recognized that immediate valve placement afteranchor implanting is contemplated.

With reference to FIG. 1, there is shown a schematic cross-section of aheart 100. A box 102 is provided to indicate an operating window formitral valve replacement. As can be gleaned from the schematicrepresentation, the operating space for mitral valve replacement islimited by the size of the left atrium 106. Whereas the left ventricle108 defines a larger space, when a repair procedure employs a leftatrium approach, the cavity defined by the size of the left atrium 106must be taken into consideration. Moreover, replacement structure anddelivery systems must be sized and configured to be passed within andthrough, as well as function within the left atrium 106. In fact, thedistance from a mitral valve annulus to a roof of the left atrium 106 isup to or approximately 4.5 cm. A delivery approach that deliversindividual components separately (whether staged in separate proceduresor not) can thus be advantageous since smaller sub-component parts canbe introduced at the interventional site and later assembled. To wit, afully assembled replacement device could be much more difficult toadvance to the interventional site and be oriented properly to effect areplacement.

It is contemplated that anchor element embodiments utilize and exploitanatomic structures and geometry to attain the required mechanicalholding forces whether engaged acutely or chronically with the additionof tissue ingrowth of the anchor. Another aspect is consideration of theanchor implant is the load distribution or force per unit of area ofanchor attachment. This can be at a level that does not allow the anchorstructure(s) to pull out of the tissue once attached. To maximize acutemechanical hold in the tissue, the profile geometry of the anchor tissueelement can be designed to maximize the breadth and depth of tissueengagement as well as the surface width and geometry of the penetratingelement. The tissue used to provide the holding force for the anchor canbe exploited such that certain regions of the mitral valve have greaterintrinsic tensile strength (e.g. anatomical gutter or trigone region) orutilize tissue that has a response that enhances the extent (thickness,area) of ingrowth (e.g. LV muscle wall). The tissue collagen orientationin certain regions needs to be accounted for if it is small chain,non-oriented fibers or can be used to maximize hold if it is largerchain and oriented collagen.

Due to the continuous and cyclical loads and motion of the system,anchor device biostability can be required, specifically fatigueresistance, corrosion resistance and overall mechanical durability. Oneof the system elements is intended to interface with tissue to form aseal. This can be the anchor forming the seal and the valve seals to theanchor, or the anchor holds valve and a valve element seals to thetissue. The implanted valve interface to anchor can provide sufficientand stable holding capability with a transfer of the valve loadeffectively onto the anchor. This may be accomplished by a frictionalfit via expansion of the valve into the anchor and/or tissue or amechanical interlock mechanism between the anchor and valve. Further,the anchor implant structure can be a biocompatible device, includingspecific biocompatibility for blood contact and tissue contact.

The specific anatomic locations that may provide mechanical andstructural attachment of the anchor is another area of consideration.The anchor may be designed to incorporate one or more of a commissurallocation such as the anterior trigone region or the posterior leafletcleft. An attachment location could also be the anterior portion of anatrial wall, or at an annular region/surface (posterior or anterior).Leaflet capture is also contemplated such as at the sub-posteriorleaflet or the sub commissural leaflet. Attachment can also be at orwithin the left ventricle (endocardial) such as to the posterior wall(including posterior leaflet capture or a papillary space wedge), theapical/sub-papillary, the anterior/posterior wall bridge, ortransmurally (septal, free wall, apex).

With reference to FIGS. 2-4, anatomical anchoring interface structure ispresented. FIGS. 2-4 depict various views of a mitral valve 110. FIG. 2depicts a top view of a closed mitral valve 110, the dashed linerepresenting the anatomical location of a gutter 120 which providesstable and reliable anatomy for anchoring a mitral replacement device.The dashed ovals represent intended locations for anchor structureengagement. The arrows included in FIG. 3 point to the left ventriclewall in a schematic representation of a CT scan cross-sectional view toprovide a sense of the anatomy defining the gutter 120 between the leftventricle wall and a leaflet edge 112. FIG. 4 provides a sub-valvularview of the mitral valve 110 to provide further details of relevantanatomy. A dashed line again depicts the location of the gutter 120, thearrows pointing to anchor structure engagement location. It is to berecognized that the complex anatomy of the native chordae 130 andpapillary muscles 132 present challenges for anchor engagement. However,there is a consistent and predictable anatomical structure pattern whichexists across patient populations. Thus, anchor engagement locationswithin the gutter 120 are chosen to avoid chordae 130 such that anchorfeet or projection are configured to be placed within defined spacesbetween chordae and hook into engagement with the gutter 120 forsub-leaflet attachment. The gutter 120 advantageously presents muscletissue having good ingrowth characteristics lending to enhancing anchorfunction. The gutter 120 also presents a space removed from leafletfunction so there is little to no impact on native heart valve operationsubsequent to the anchor placements. The fibrous trigone 134 (See FIG.2) additionally provides a high collagen, structure element for acuteanchoring.

Further details concerning the gutter 120 can be understood from FIGS. 5and 6, which depict a schematic cross-section of a left ventricle wall140, a fibrous annulus 142 and posterior leaflet 144 of a heart. Thegutter 120 exists both when the leaflet is open and closed and definessufficient space to receive structure of an anchor device. FIGS. 7 and 8provide further views of gutter space 120, indicating points whereanchor structure 160 passes sub-valvular structure, and into the gutter.FIG. 9 additionally depicts a sub-valvular pocket 152 residing below theposterior leaflet (shown in a partially dissected heart), the sameproviding a convenient and effective space for receiving anchorstructure. FIG. 10 depicts a V-shaped tent of chordae 154 connected toleaflets which again shows the space available for passing anchorstructure into engagement with the gutter. Thus, a well-defined anddistinct plane exists between chordae and the left ventricle wall whichlends itself for the passage of loop or other structure withoutentanglement or loss of function.

Turning now to FIGS. 11-15B, various approaches to anchor loading pointsare discussed. With the valve leaflet 144 closed (FIG. 11), there isagain a well-defined gutter 120 presented for anchoring structures. Asshown above in connection with FIGS. 9 and 10, anchor structure can bepassed between well-defined spaces among chordae 130. Should anchoringstructure 160 be applied directly to a leaflet tip 144 (FIG. 12), loadis distributed onto the chordae 130 and down to the papillary muscles132. With such an arrangement, the leaflet 144 can become lax and thusaffect heart function. Where anchor structure 160 is placed beneath theleaflet 144 (FIG. 13), load is roughly distributed evenly (representedby location of up arrow) between the annulus 142 and through the leaflet144 to the chordae 130 and into the papillary muscle 132. Loads are thusdistributed to natural load bearing structure but loading vectors (downarrows) still have different values.

In yet another approach (FIG. 14), load (represented by up arrow) can beapplied by anchoring structure 160 directly to the annulus 142 by takingadvantage of sub-annular anatomical geometry. Here, the leaflet 144 canhelp ensure that the anchor structure 160 is maintained in positionbelow the annulus 142, both in a closed position (chordae 130 showntaut) and an open position (chordae 130 shown lax). In this way, thevalve leaflet 144 remains competent until valve replacement structure isimplanted as forces are applied to the annulus 142 but not the leaflet144 or chordae 130.

As shown in FIGS. 15A-B, a supra-valvular leaflet anchoring approach isalso contemplated. Anchor structure 160 is placed into engagement withthe annulus 142 from above the leaflet 144. Here also, loading isdirected to the annulus 142 but not to the leaflet 144 or chordae 130.

It is to be recognized that the mitral annulus is typically nonplanar,non-circular in shape, flexible and distensible. These all contribute toa complex substrate to effectively attach an artificial valve, andspecifically the anchor structure. The anchor itself can thus includevarious approaches to support the skeletal structure. In one approach,the structure can be a supra-valvular structure with commissural feet.The commissural feet/projections can be structures which aremulti-functional elements that can provide mechanical/geometricanchoring, penetration (needle/barb like) securement, and tissue basedincorporation (in-growth) including subvalvular/sub-leaflet structuresthat extend into the LV wall, all of which do not interrupt leaflet,chordae or native valve function. Also, they can provide a positioningbasis for the entire anchor because of their engagement with thecommissural clefts in the anterior and posterior leaflets while stillavoiding interaction or disruption of the chordae or native leaflets.

A ring structure can be designed to provide a D-shaped or alternativelya relatively circular, non-distensible, non-elongating homogeneous framesubstrate that the artificial valve can engage and attach to during itsdeployment. This structure may be continuous or interrupted, andcompletely around annulus or only partially around annularcircumference. Moreover, portions of the anchor can be sinusoidal inplane of valve leaflets trying to create continuous attachment aroundentire circumference (each sinusoid comes in and out of plane) orsinusoidal perpendicular to valve bridging from point to point creating,multiple attachment points, thereby allowing for tissue ingrowth betweensinusoidal points of native leaflet or annulus tissuecontact/engagement. The anchor can be malleable with points ofattachment between commissures, a single wire or multiple connected wirecomponents, or be formed into a saddle configuration to approximatenatural saddle geometry of valve (may be based off of 3d echo or CT todetermine geometry).

There may further be a covering of the skeletal frame of the anchor. Thecovering of the anchor skeleton can provide opportunity for facilitatingcollagen tissue ingrowth into or onto the implant structure and/orcovering in locations such as on top (atrial side) of leaflet orannulus, at side of leaflets or annulus, at a ventricular wall atsub-valvular level, or underneath (ventricular side) of the leaflet orcommissures.

A superstructure above the valve annulus may provide options for valveattachment to the anchor or even an alternative therapy such as mitralreplacement via a septal lateral cinch. Various superstructures abovethe annulus can include A2 P2 points of attachment, two circles to allowfor double aortic valves, or use of the atrial wall behind A2 or P2.

Materials for components used in multiple combinations andconfigurations, may include metals, especially for the anchor skeletonor frame structures such as Nitinol because of its superelasticity andability to be compressed into a deliverable shape/state and thendeployed into a functional state, titanium due to its strength andbiocompatibility, stainless steel: hardened for its strength ormalleable to aid in conforming to shape, cobalt/chromium alloy forstrength and known valve component implant history; or composites toprovide multiple properties based on anatomic location. Tissue elementsalso may be incorporated on the anchor implant to aid overall functionof holding or tissue engagement and sealing including pericardial(bovine, ovine, porcine) tissue or valve tissue (bovine, ovine,porcine). Further synthetic polymers can be used as biocompatibleelements in implants and on the anchor due to their know tissue andblood compatibility properties. These can include Elast-Eon (a siliconeand urethane copolymer), ePTFE, urethane, silicone, PEEK, polyester(PET), or UHMWP.

Geometric/mechanical holding force for anchor that exploits thegeometry/configuration of anatomic structures (relative to force vector)to achieve the necessary holding force required by a deployed artificialvalve or other therapeutic element is further contemplated. The forcevector encountered by the anchor structure's commissural projections aresubstantially under shear loading verses a perpendicular load relativeto the tissue. Commissural projections or foot elements that are able todeploy behind the anterior and posterior leaflets in the gutter wherethe leaflet meets the annulus provides for direct mechanical holdingcapability. The commissural projections of the anchor structureconnected and bridged to each other provide an ability to create amechanical wedge structure to resist the force and hold the valve inposition. LV wall projections of the commissural feet can provide forthe ability to develop deep tissue penetration elements into the muscle,wider elements to increase surface area of contact/attachment, andlonger projections to increase holding capacity. Moreover, because theprojections can be placed such that they are supra annular andsub-annular, a C like structure in cross section can be utilized that iseither connected or clamped. With regard to tissue penetration basedsecurement, direct mechanical holding force is contemplated for ananchor that utilizes the natural strength of the LV and leaflet tissuesto hold onto anchor structure. These elements can be configured toeither be inserted into the tissue and resist pull out (barb like), orthey may go into and out of tissue to provide a tissue “bite” like astitch, or both elements can be employed. The structure can be locatedposterior annulus or entire annular perimeter, or adjacent leaflettissue, the trigone/anterior annulus, an endocardial LV surface or LVMuscle tissue. Further, the tissue penetration securement elements canbe linear (staple or nail like), helical (rotation axis is perpendicularto tissue interface or rotation axis is parallel to tissue interface(in/out/in/out)), curved and or curled, or bent (L shaped or S shaped).

As stated, it is also contemplated to use chronic ingrowth to providelong term stable implantation of the artificial valve and proper sealingfunction. In addition, chronic ingrowth of implant structural elementscan serve as a fundamental mechanism to achieve the necessary holdingforce of the anchor functional element of the system. It exploits thenatural healing response to foreign bodies placed into tissue and theblood stream to develop a strong collagen based tissue connectionbetween the implant surface structures and the native valve tissue witha possible endothelial surface. This can be achieved while stillmanaging the response to prevent unwanted damage to anatomic structures,damage to blood elements, or creation of thromboemboli.

More areas of consideration are the surface composition elements,specifically the material choice and texture to promote tissue reactionand device incorporation with maximal force holding capability. Theseelements can also be incorporated onto the tissue penetration elementsto further increase the holding force by incorporation deep into tissuerather than just at the surface. The anchor can have a gross surfacemodification (barbs, slits), a surface texture/pores to promote ingrowthand mechanical hold, a fabric material covering (Dacron velour, doublevelour, ePTFE), a wire brush (multiple short wire elements) or anadhesive. There can further be a single or multiple points ofattachment, planar attachment or by way of a confluent surface.Moreover, the tissue/anchor interface can be rigid or flexible and caninclude a wire frame structure that puts a compressive force ontosurface contact interface to promote increased response. Also, tissuesurface modification can include an abrasive, a chemical irritant topromote inflammatory response or application of heat.

In current conventional approaches to valvular intervention, adiagnostic echocardiograph is initially performed to assess valvefunction followed by two percutaneous procedures. First, a diagnosticangiography is performed with or without a right heart catheterizationto assess, for example, whether they might also requirerevascularization first, prior to valve intervention. Here, patients donot receive valve therapy without the patient being fullyrevascularized. Thereafter, at a different time and place, valvereplacement therapy is performed involving fixation/attachment,accomplishing a tissue sealing interface, and valve deployment and thenrelease. In contrast, the presently described approach, however, caninclude an assessment involving a diagnostic echocardiography followedby a unique percutaneous valve procedure sequencing. First, a diagnosticangiography (+/−right heart cath) can be performed along with anchorfixation/attachment and anchor/tissue sealing. Subsequently, eitherlater or during the same interventional procedure, valve replacementtherapy can occur involving valve deployment and release. Thus, sincethe anchor implant allows the native valve to remain functional, theanchor implantation procedure could be added to the end of the angio(+/−PCI), and not require a separate interventional procedure. A quick,simple, and reliable anchor deployment could permit a fully ingrownstructure that significantly enhances the holding force of asubsequently implanted replacement valve. Tissue ingrowth of the entireanchor perimeter, or at key positions thereon, can in fact provide thenecessary tissue seal in advance of valve deployment. Moreover, theanchor design could be simplified due to less required acute holdingforce. Therefore, a tissue incorporated and healed anchor provides astructure to perform several methods of annular adjustment, includingplication, reduction annuloplasty, and septal-lateral cinching.

In one specific embodiment, an anchor assembly 200 can be embodied in aframe 202 including supra-annular and sub-annular structure (See FIGS.16-19). The anchor assembly is designed to not interfere with nativevalve function, allowing it to be placed some time prior to areplacement valve without degradation of valve function during theperiod of time between the anchor implantation and the valveimplantation, whether that time is on the order of minutes, or evenseveral days or months. It is also to be noted that the frame can beformed from a single continuous wire, or created compositely frommultiple wires. The diameter or width of the wire or other structureforming the frame can range from up to 0.016 inches to 0.0235 inches ormore (FIGS. 16 and 18 show the anchor with a fabric covering 204 andFIGS. 17 and 19 show the frame without covering.) A generally D-shapedcentral ring 210 is sized and shaped to be received at, above, or belowa mitral valve or other annulus. This ring can assume a diameter ofabout 28-36 mm when circular or a commissure to commissure dimension ofup to 30 mm to 40 mm or more and an anterior to posterior dimension ofup to 20 mm to 30 mm or more and can be formed from an element having adiameter or width that ranges from up to 0.010 inches to 0.018 inches ormore. Also, a circular valve interface to ring dimension can range fromup to 28 mm to 36 mm and a D-shaped valve interface to ring dimensioncan range from up to 30 mm to 40 mm (commissure to commissure) and up to20 mm to 30 mm anterior to posterior tip. Moreover, the anchor 210 canbe configured such that portions thereof reside both above and below anannulus.

Extending from the central ring 210 are a plurality of projections orfeet 214, 216. Such projections are sized and shaped to engage thesub-annular, valve gutter described above. A first pair of projections214 are sized and shaped to each extend through one of anterior andposterior commissures and engage within or adjacent the trigonestructure. In one approach, the projections can be spaced approximately30-45 mm. Also, the projections can have a height ranging from up to 8mm to 12 mm or more, and have a gutter engaging surface area rangingfrom 10-24 mm². The width of the projection can range from 2.5 to 4 mmor more and have a length ranging up to 8 mm to 12 mm or more. A secondpair of projections 216 are supported by or extend from downwardlydirected arms 220 which are at an opposite end supported by the centralring 210. A distance between the first and second pair of projectionscan be about 20-33 mm. Such arms 220 are configured when implanted toextend from the central ring 210 through the boundary between theanterior and posterior leaflets. From their connection or support pointswith the arm 220, each individual projection of the second pair ofprojections 216 extends upwardly and at an acute angle. The projections216 are sized and shaped so that when implanted they avoid interferencewith mitral chordae, valve leaflets, and papillary muscles. Terminalends of the projections are further configured to be sized and shaped tobe received within and engage a posterior portion of the sub-annulargutter (as shown and described above).

The sub-annular structure of the anchor frame 210 further includes acentral hub 220 which can both function as structure employed as areleasable connection during device delivery, as well as a base fromwhich sub-annular support arms 222 extend, one to each projection 214,216.

The supra-annular structure of the wire frame 210 includes an anteriorapron or visor frame 230 and a smaller posterior apron or visor frame232. A wire forming these frames can range from up to 0.016 inches to0.0235 inches or more, or up to 0.016 inches to 0.030 inches or more,respectively. As best seen in FIGS. 16 and 18, the apron frames accept afabric material there across. The apron provides stability from downwardforces during left ventricle filling. A skirt 236 extending below thecentral ring 216 is further provided for tissue ingrowth and for longerterm sealing against leakage between native valve leaflets and ananchor/valve assembly. In one or more approaches, the anterior skirtheight can be about 6-12 mm with a flare range of 110-180 degrees, andthe posterior skirt height can be 4-10 mm with a range of about 110-180degrees. Ventricular support structure can further range from 10-15 mmfrom a leaflet tip. FIG. 20 depicts one embodiment of a valve assembly300 received by the anchor assembly 200. The valve assembly 300 caninclude a waist which receives the central ring 210 (See also FIG. 31).FIG. 21 shows a fluoroscopic image of the wire frame of the anchor andvalve assemblies implanted within an interventional site. The anchor andvalve assemblies can be configured so that the valve resides entirely orpartially within the left atrium.

Another embodiment of an anchor assembly 250 is depicted in FIGS. 22 and23. Rather than being formed from a continuous or segmented wire, thisanchor 250 is defined by a flat or ribbon structure. Such structure canhave a width of 0.035-0.050 inches and a thickness ranging from 0.008 to0.015 inches. In one approach, the anchor can be laser cut from a tubein its final form, or cut from a tube and later formed into a desiredshape. In one embodiment, the anchor 250 is configured to formprojections 252, 254 for engaging a gutter formed in natural tissue, andincludes a central generally D-shaped ring 256 sized and shaped toengage a valve to be positioned proximate or at a valve annulus. Themembers defining the ring can have a width of 0.012 to 0.020 inches anda thickness of 0.0115 to 0.015 inches. The device further includesanterior and posterior frames 258, 260 defining aprons or visorsconfigured to stabilize the anchor within the interventional site asdetailed above. The numbers defining the visor can have a width of0.012-0.020 inches and a thickness of 0.0115 to 0.015 inches. Extendingdownwardly from each projection 252, 254 individually and toward a hub262 is a support arm 264. An eyelet 266 formed at the hub 262, and theeyelets 268 formed on the apron frames 258, 260 define structure thatcan be employed to facilitate delivery of the anchor 250 at aninterventional site. Ventricular support structure can have a widthranging from 0.042-0.060 inches and a thickness of about 0.015-0.020inches.

Certain areas of the anchor 250 can be widened, such as feet orcontacting portion of projections 252, 254 to present a desired contactpressure at an annulus. These projections can have a height ranging from8-12 mm, a surface area of 6-15 mm², and width and lengths of 2-3 mm and3-5 mm, respectively. Also, by embodying the flat or ribbon profile,thinner material can be employed in the anchor 250, thus facilitatingdeliverability by enabling the device to be compressed to a smallerdimension. The ribbon structure also lends itself to improved results tomaterial fatigue where a wider aspect of the ribbon can be placed orconfigured to offset forces. It is to be further recognized that theanchor 250 is contemplated to be covered with material for ingrowth andother functional reasons. For example, as with the embodiment above,material covered aprons function to aid in directing blood flow from theatrium to the ventricle.

Turning now to FIGS. 24 and 25, there is presented a schematicrepresentation of an alternative embodiment of a frame of an anchor 270placed at a mitral valve MV. This particular approach to an anchor 270includes an anterior apron 272, but lacks a posterior apron. Anteriorprojections 274 extend from a generally D-shaped central ring 275 andengages directly under the trigones T. A pair of posterior projections275 also extend from the central ring 275 and into the gutter adjacentthe posterior portion of the posterior leaflet PL.

In yet another approach (FIGS. 26-28), an anchor 280 can include agenerally D-shaped ring 282, and a plurality of projections 284extending from the curved side of the D-shape. As described before, theprojections 284 are sized and shaped to extend to within the gutter 140to accomplish a seating and securing function. In the embodimentdepicted, the posterior leaflet PL is essentially captured by theprojections 284. Thus, in a replacement approach employing this anchor280, it may be desirable to immediately follow up implantation of theanchor 280, with the insertion of a replacement valve. In the meantime,the anterior leaflet can provide adequate coaptation until the valve isset.

FIG. 29 depicts yet another approach to an anchor device 290. Anteriorprojections 292 are sized and shaped to be received within and engagedirectly under the trigones adjacent the anterior portion of a valveannulus. An anterior cross-bar 294 provides stability to the anchor 290placed at or near a valve annulus. A posterior portion 295 of the anchor290 defines a sinusoidal shape and can be designed to hold the posteriorleaflet of a mitral valve. Again, the anterior leaflet of the valve willprovide a closing function by engaging the sinusoidal portion 295 of theanchor device 290. The loading of this anchor 290 is primarily curved bythe leaflet tips to the chordae connecting the posterior leaflet.

As stated, staging is the ability to stage the implantation of valvestructure so that it could be deployed in the same procedure as that ofthe implantation of anchor and sealing structures, or thereafter. As theanchor and sealing structures grow into and are incorporated in thetissue/existing anatomy, the holding capability of these structuresincreases until such time as the valve/assembly is deployed, eitherautomatically (e.g., suture dissolving over time) or by some triggermechanism or actuation during a second procedure. This actuation couldbe achieved remotely without invading the body (e.g., RF orultrasound-like actuation).

The valve replacement system according to the present disclosure allowsfor valve delivery flexibility. Specifically, tissue valves can bedelivered either via a fully percutaneous procedure or a minimallyinvasive surgical delivery of the valve without modification to thevalve implant to accommodate the alternative route.

Yet another aspect of having a stable consistent anchor platform forreceiving a valve structure is that it allows for valve sizing that isappropriate for the patient population (FMR, structural, mixed) and evenspecific to the patient being treated. In other words, it allows for thelargest valve possible in every patient rather than compromising size(smaller than physiologically desired) to accommodate technologylimitations in systems that must combine multiple (increase complexity)valve, attachment, sealing and delivery structures.

The system according to the present teachings also allows fortherapeutic flexibility of the artificial valve. The presently disclosedsystem allows for beating heart implantation of both tissue andmechanical valves. As disclosed herein, delivery systems are providedthat allow implantation of mechanical valves via either a trans-apicalor trans-atrial thorascopic route.

Moreover, while surgical tissue replacement valves in the mitralposition have conventionally often been basic and inverted modificationsof the tri-leaflet aortic counterpart, the percutaneous deliveryrequirements (collapse/expand) of the TMVR allows for designs specificto mitral position on several functional requirements. For example,there is sufficient size for blood inflow so as to not traderegurgitation for stenosis. One key aspect is that in functional MR withnative annular dilatation, the replacement valve does not need to fillthe whole annular area of the now dilated annulus. A smaller area can beused while still creating sufficient size to prevent any inflowobstruction/stenosis. Also, it is desirable to maintain LV chordalconnections and geometry to maintain LV functional geometry and stressconfiguration. Cutting or disruption of the chords can createsignificant increases in LV wall stress and resultant loss of cardiacfunction.

A durable valve design balances sufficient valve height relative to thediameter to prevent excessive post loads and leaflet stresses. In themitral position (vs. aortic) this is accentuated with the generallylarger valve diameter requirement (lower through flow pressure) and thehigher valve loads encountered when closed (LV systolic pressure vs.diastolic aortic pressure). In surgical replacement mitral tissuevalves, the valves are designed for the base to be sewed to the annulusand the stent leaflet posts extending from the base, but are short tominimize LV depth to prevent outflow tract obstruction or native leafletentanglement. In these valves, the base also tends to be designed as acylinder and therefore is not extended into the atrium to preventpotential pockets of stagnated blood.

Sealing against the native valve is to be a consideration. A valve thatrelies on radial expansion and or compression to create the sealrequires a valve frame that is larger than the native annulus and alarger radial force to create the interface. Sufficient anchoringinterface and holding is also an important consideration. Valves thatrely on frictional interface to create anchoring force requirerelatively larger radial expansion force capability increasing thecomplexity of the stent frame. Ability to collapse into a deliverableconfiguration and then reliably expanded configuration can be addressedas well as the prevention of LV outflow tract obstruction. Too great ofan encroachment into the LV beyond the native mitral annulus can impactthe position and function of the native anterior leaflet. If it ispushed too far down and out, it can be pulled into the outflow tractduring systole creating functional obstruction of the LV outflow tract.Moreover, prevention of flow stagnation regions to prevent clotformation and embolization can be important on both the atrial side aswell as the ventricular side, specifically in the sub-leaflet gutterregion.

Regarding these final two considerations, aortic valves that are beingmodified to use in mitral position as well as surgical valvesconventionally all have a generally tubular design at their base regionor beyond up into the commissural post region. This tubular design thatbridges across the native mitral valve has the possibility of creatingoutflow tract obstruction and pockets of stagnation behind the valve andnative leaflet region if it extends too deep into LV or can createsignificant flow stagnation regions if the “tube” extends too far intoatrium with blood having to flow up and over the valve base to reach LVduring diastole. Additionally, the use of a tubular symmetric valve in aD-shaped mitral annulus may result in uneven distribution of stressesacross leaflets and therefore reduced durability.

Thus, in one contemplated embodiment of a percutaneous replacementmitral valve, there is structure for facilitating an optimum valve forthe mitral position. With respect to atrial biased positioning, thecontemplated valve is positioned with a bias to the atrial side with theLV side only extending to or short of the commissural and posteriorleaflet tips when they are in the diastolic position (vertical to LVwall). This allows for minimal interference with native leaflets andchordal connections, minimizing engagement and interference with theanterior leaflet therefore minimizing potential for outflow tractobstruction, minimizing sub-leaflet (LV side flow stagnation andpotential for clot formation and embolization, and allows for sufficientvalve height to manage commissural post strain and leaflet stresses.Taller or longer leaflets for a given valve diameter have smallerleaflet stresses.

The contemplated approach is also contemplated to embody a “ring inring” stent design. Here, this is an inner ring for large circularleaflet/occluder geometry for optimum function and durability. The innerring can consist of the 3 commissural posts joined by the 3 arches andthe 3 leaflet cusps sewn to the posts and arches. This structuralrelationship that allows the outer ring to deflect and adapt to thenon-circular native anatomy while maintaining circular inner geometryallows for overall better valve performance and maximizes durability.Another aspect of this configuration is that the leaflet excursionduring diastole where the leaflets define a circular shape is that theleaflets do not impact or come into contact with the outer supportframe/ring reducing the likelihood of damage to the leaflet tips as canhappen with an overall circular support frame. Moreover, it iscontemplated that the leaflets can be formed from glutaraldehyde fixedpericardium or aorta cusps from one or more of a bovine, porcine, ovineor equine, and having a thickness of 0.005-0.020 inches or specificallybetween 0.008-0.012 inches and being anisotropic (collagen fiberscircumferentially oriented) such that modules in one direction is higherthan another (E circumferential>E radial).

The replacement mitral valve also includes central support ofcommissural posts (vs. base) to minimize cyclical strain and improveddurability. Loading during leaflet closure is translated to the postsand creates tip deflection toward the valve center. Having the postssupported more to the middle of the overall stent frame helps minimizecyclical strain and therefore improves durability. The longer posts andleaflet height combine with a more centrally supported post to improveoverall durability due to more uniform distribution of stresses betweenthe leaflets. Further provided is an outer ring for adaptable sealinginterface and native valve engagement. The outer ring can adapt to thenative leaflet and valve shape and size while maintaining the centralcore inner ring.

The contemplated replacement valve can also include a scalloped orarched leaflet cusp design. With the more atrial positioned valve, thescalloped arches or cusps help minimize atrial flow stagnation bothduring diastole when the leaflets are in the open position, the bloodflows between arches which sit proximate the native annular height, andduring systole as the backside (non-leaflet side) of each arch is alsopressurized and creates dynamic motion behind the cusps. Traditionaltubular design valves have no such capability. With the leaflet cuspssewn to the arches, there is also efficient load transfer from theleaflets to the arches and then to anchor structure, also minimizingstent deflection/strain and enhanced durability.

The replacement valve is also contemplated to include a receiver waistfor engagement with the anchor. The waist of the valve engages with theanchor ring structure to provide for a simple geometric interlock forload transfer to the anchor rather than frictional fit to anchor or thenative valve. Therefore, the radial strength of the valve is less thanrequired if a frictional fit was used; it needs to be properly sized,but does not require radial force expansion into the anchor ring.

Additionally, collapsibility, expression, repositioning, and recapturingof valve are all further requirements or desirable aspects of theoverall valve design. The current embodiment has several elements thatcontribute to an improved capability to perform these functions. Thatis, the potentially lower radial force required for the overall valvedesign can allow the valve to collapse with less force both initiallyduring insertion into delivery catheter, as well as when the valve mayneed to be partially collapsed for repositioning, or fully collapsed forrecapture and removal. Also, the arches of the valve create an improvedleading edge (rather than a collapsed cylinder) for the valve to beretrieved into the delivery sheath if needed, provide natural points ofholding and individual control during expression and deployment, providelower regional outward radial force that facilitates holding duringdeployment into the anchor as well as during recapture. The arches orscallops can allow the valve to partially function during placement fora more controlled implant with less potential for negative hemodynamicconsequences to the patient. Also, attachment to the arches allows forfunctional assessment of valve prior to final release. The three pointsof proximal hold also create the ability to control the planarity of thewaist section of the valve so it becomes coplanar with the anchor priorto full deployment. The three inner posts also may provide a distalholding point during delivery.

Accordingly, referring to FIGS. 30-38, there is presented one particularapproach to a valve 300 embodying a number of the above-identifieddesirable valve features. Various views of the valve frame 310 alone areset forth in FIGS. 30, 32, 35 and 36 to provide a sense of its overallstructure. In FIG. 30, only the foreground structure of the frame isshown so that a repeating pattern can be best appreciated. FIG. 32 showsa top view of the cylindrical D-shape of the frame 310. As best seen inFIGS. 32, 35 and 36, the frame 310 includes an undulating ring 312having three arches 314. Each arch 314 defines a generally parabolicprofile having a loop 316 at its apex and adjacent arches 314 beingconnected at their bases to form commissural posts 318. In oneparticular embodiment, the members defining the frame have a thicknessof up to 0.012 to 0.024 inches, and can be in the range of 0.016-0.018inches.

Attached to anchor ring 310 are a plurality of closed cells 320.Although the cells 320 can assume various shapes, as shown, whenexpanded, each cell includes upper and lower narrowed ends and a widemid-section. There is an interrupted first row of such cells 320circumventing a bottom portion of the frame 300, such cells 320 beinginterrupted by a half cell 321 longitudinally aligned at eachcommissural post 318. A second interrupted row of cells 320 areconnected to and reside up above the first row of cells 320. Uppercurved arms of the lower set of cells 320 define a lower section of theinterrupted upper row of cells 320. The upper row of cells 320 areinterpreted by members of adjacent arches 314 leading to the commissuralposts 318. Additional support is provided by extending members 322extending from upper ends of members defining the half cells 321, tothereby define a larger V-shaped cell 326 encompassing each of thecommissural posts 318. Curved arms also extend from the upper narrowportion of the second row of cells 320 to an arch. Further, configuredat the base of each of the closed cells 320 and the half-cell/V-shapecells 321, 326 are loops 330. Such loops can be engaged by devicedelivery structure for accomplishing implantation. FIG. 32 in particulardepicts an isosceles triangle arrangement of the inner posts (ring).

As best seen in FIGS. 30, 35 and 36, the frame embodies a waist 301. Asdescribed above, this waist 301 is sized and shaped to receive an anchorimplant. In one embodiment, the waist is 18-34 mm anterior to posterior,and 20-44 mm commissure to commissure. A ratio between the same can be0.5 to 1. Moreover, when applying tissue or fabric 333 to the valveassembly 300, as shown in FIG. 31, the waist remains. Flaring of thevalve assembly can result in an anterior to posterior dimension of 20-40mm, a commissure to commissure dimension of 24-50 mm, and a ratiobetween the same of 0.05 to 1. The total valve height can be 20-36 mm(with the underlying frame having a post to arch tip dimension of 20-36mm), and the valve can embody a 17-33 mm effective diameter.

With reference to FIG. 33, a top view of the valve assembly 300 is shownimplanted within an interventional site. It is noted that while theindentation region of the assembly can resemble a D-shape, the valveorifice 334 is generally circular for optimal valve performance. FIG. 34provides a bottom view of a closed valve assembly 300 implanted at aninterventional site. FIGS. 37 and 38 are provided to show ventricularviews of an implanted valve assembly 300 in closed and open positions,and with a flaring 336 of the valve frame 310 and tissue or fabriccreating a component sealing surface with anatomy.

An anatomical side view of the valve assembly within tissue isrepresented in FIG. 39. Here, a fluoroscopic dye 350 has been injectedinto the left ventricle area to assist with showing anatomy viafluoroscopy. The dashed line follows the native mitral valve plane 352.The frame 310 of a valve assembly can be seen implanted above the leftventricle. Note that the dye is contained within the ventricle,indicating good valve performance by the implanted valve assembly.

The requirements of the sealing interface with the native valve includeventricular to atrial sealing during systole, atrial to ventricularsealing during diastole, and stable chronic sealing that results fromingrowth incorporation of the sealing interface with the native valve.One approach to sealing is to utilize a native tissue engagementstructure with the native leaflets along the annular perimeter to createa LV pressurized seal. This is not a mechanically compressive orattachment (active fixation) seal onto the native tissue. It alsorequires minimal or no radial expansion beyond the tissue engagementinterface. In one contemplated embodiment of the percutaneous mitralvalve, the frame is externally covered by tissue. During systole, thetissue expands radially reaching out to the native valve to create aparavalvular seal. The external tissue also expands radially on theatrial side cuff (outer covering on valve) to create a supra annularseal during systole.

As shown in FIG. 40, an anchor frame 200 covered with fabric 204 can beplaced proximate an annulus of a natural valve including leaflets 144. Areplacement valve assembly 300 is placed into engagement with the anchor200 by positioning the waist 301 of the valve assembly so that itreceives the anchor 200. Thus, fabric such as Dacron of an anchor frameis placed adjacent native tissue on both ventricular and atrial sides ofa valve annulus thereby facilitating a seal. Pericardial tissue (e.g.one or more of glutaraldehyde fixed ovine, equine, porcine or bovinepericardium having a thickness of 0.0005-0.036 inches, or 0.05-0.014inches) 360 is further provided on the valve assembly 300. The fabric204 of the anchor 200 interfaces with the biological tissue 360 of thevalve assembly 300, thus facilitating a seal between the anchor 200 andvalve 300. Moreover, the atrial position of the valve 300 is selected tofacilitate a sealing surface to be at or near a collar of the valveframe and adjacent to the valve annular region to endeavor optimizingoverall perimeter engagement of the sealing surface as seen in FIG. 40Ataken in cross section just below the Dacron 204 of the anchor (i.e.anterior leaflet region, commissural region, posterior leaflet region).

Next, imaging and implantation is discussed. Relevant aspects of imagingare to evaluate valve function pre- and post implantation, and tofacilitate proper positioning of the implant components. Echo imaging,either ICE or TEE is sufficient and available for valve functionassessment. Imaging for device position is more complex and requiresestablishing repeatable and consistent views (imaging planes) andreference landmarks (device relative to anatomic structure or otherdevice) to reliably and accurately position the system. Imaging fordevice placement preferably also includes fluoroscopic imaging.

As shown in FIG. 41, side, top and back views of a mitral valve comprisethe orthogonal views which are useful in an implantation procedure. Asdescribed below, once an orientation tool is in position across a mitralvalve, using a self-orienting loop with tactile feedback, C-arms of afluoroscopy machine are lined up with markers on loops of theorientation device to establish registration angles that correspond withviews relative to the mitral valve for delivery and replacementcomponents. By doing so, the mitral valve, which is not easily visibleon fluoroscopy, can be confidently targeted by virtue of properlyaligned angles on the fluoroscopy machine.

One approach to understand in the intra-procedure device position is toestablish orthogonal views of the valve annulus, ventricle, and atrium.In order to assess target anatomy, an orientation loop 400 (See FIGS. 42and 43) can be placed in the coaptive margin between the anterior andposterior leaflets, and employed to establish implantation sites andreference points.

In one approach, a catheter 400 is provided with orthogonalloops/structures, one large 402 and one small 404 that can be advancedinto and above the valve, respectively, and can be attached to anelongate member 406 extending from the loops to an operator. It is to benoted that the large loop will be positioned within the coaptive marginsuch that the anterior and posterior chordal tents will orient the framebased on the leaflet tips engaging the sides of the frame and possiblymore importantly, the chordal tent plane between the anterior andposterior chords engaging along the entire sub-valvular extent of theloop 402 (See Also FIG. 44). The distal (bottom) end of the smaller loop404 will be positioned at the valve plane by both tactile andfluoroscopic visualization (bounce/deflection) as it interacts with theleaflets. FIG. 45 depicts the use of the orientation loop 400, showingthe large loop 402 fully expressed and the small loop 404 in alignmentwith the elongate member 406. FIG. 46 is a side view showing the largerloop 402 fully expressed/expanded, both arms of which being in alignmentwith the elongate member 406 and the small loop 404 extending over thevalve leaflet.

Referring to FIGS. 51-53A, one can further appreciate the positioning ofan orientation loop within valve anatomy. Again, the tool 400 is placedthrough a valve MV and positioned so that the large loops 402 of thedevice are placed along the coaptation margin of the valve. Byregistering markers 410 positioned at the extreme width of the largeloops 402, as stated, the angles of the views can be registered forfluoroscopy and ultrasound equipment for later use in anchor and valveplacement and orientation, knowing that the orientation of the anchorand valve themselves will not be easily identified by remotevisualization. Measuring the native annulus dimensions via theorientation loop markers 410 with fluoroscopy can also be performed.FIGS. 53B-E depict further detailed structure which can be relied uponto determine orientation. Markers 410 can be banded, including darkregions 412 and light regions 414. They can also include a plurality ofradiopaque or other aligning dots or sub-markers 416. The relativeposition of the aligning dots 416 can be used to determine therotational position of a marker 410, and thus the structure to which itis attached (See FIGS. 53B-C). Moreover, axial alignment of a marker410, and thus the structure to which it is attached, can be determinedby observing whether an angled (FIG. 43D) or true side view (FIG. 53E)is presented.

These two frame loops 402, 404 can thus assist in establishing thedesired camera positions for back, side, and En face (top) views (viewsshown in FIG. 41). By moving the camera (not shown) until the imageindicates two orthogonal lines (en face), one large loop with short linein top center (CC Side View), or one small loop with long line extendingthrough loop and down into the left ventricle. Further, the commissuralline and position can be established based on the large loop 402orientation being parallel to commissures which can be confirmed in theshort axis echo image which will indicate commissural points and two“dots” indicating cross section through the large loop. In this way, adetermination can be made concerning the location of the valve leafletplane during systole. Next, a guide catheter tip can be oriented to bedirected at the valve center in the x, y, and z axes via the wireextension from the loops being linear with each loop in each side imageplane to thereby establish imaging planes.

Alternative embodiments of an orientation tool are provided in FIGS. 47and 48-50. In one approach, the orientation tool 400 can include thelarge loops 402, but the elongate member 406 terminates at the beginningof the loops, or the device otherwise lacks a generally straightlongitudinal member extending through the loops. Moreover, a small loop420 is defined by a generally circular member configured orthogonally tothe large loops 402. The orientation device 400 shown in FIGS. 48-50resembles that presented above in connection with FIGS. 42 and 43. Thesmall loop 422 defines a path like the small loop of FIGS. 42 and 43,but again, lacks an extension of the elongate member passingtherethrough.

It is to be noted that the dual orthogonal loop structures can be usedas a structure to pass cleanly through the mitral sub-valvular apparatuswithout chordal entanglement. Once the imaging planes are established,reference landmarks can be used to direct the insertion of an anchor,especially on depth relative to the valve plane. In particular, thedepth of the leaflet tips during diastole could be established for footinsertion depth.

With respect to orientation/positioning methods, utilizing a separatelyimplanted anchor substrate is the ability to utilize a fluoroscopicalignment technique to mesh the anchor with the valve. In this scenario,the x-ray fluoroscopic camera could be adjusted so a radiopaque(complete or interrupted around perimeter) anchor structure would bevisualized in a relatively straight line (camera orientation—lineconnecting emitter with intensifier—is perpendicular to anchor circularaxis, or parallel to plane of anchor ring). The valve frame structurecould similarly have a radiopaque perimeter at the point at or near theinterlock region with the anchor. When the anchor was viewed in themanner described, the valve axial orientation could be adjusted so theradiopaque perimeter was also a line (without moving camera position)meaning the two cylindrical axes of the anchor and valve were nowparallel. Subsequently, the valve line could be appropriately positionedabove, below, or at the interlock region. This linear alignment of thetwo radiopaque structures would be even more visually pronounced as thevalve frame was being expanded/deployed, whether by balloon orself-expanding. This could additionally allow for fine tuning oradjustment prior to final engagement of the valve with the anchorstructure.

General fluoroscopy based methods can be used to evaluate use ofmarkers/overlays on a fluoro screen within the same camera/tableposition. It is noted that some equipment has built in markingcapability within an image view. Further, device length markers in theform of a pigtail with 1 cm marks (useful in the Back view where pigtailis running through center of image) can be employed as can a wire with 1cm marks along distal length, such as 1 cm marks on the pusher shaft.Further, dye injection methods are contemplated to better viewsub-leaflet structure (with a curved diagnostic catheter placed sub-P2).Visible or augmented anatomic landmarks are of course to be consideredincluding use of a guidewire in circumflex and tracking of the ICE probeor guidewire into coronary sinus. Finally, evaluations using echo LAXviews to see leaflet tips in foot locations are contemplated.

After setting remote visualization equipment using the orientation tool,it is contemplated that a positioning frame may be used to guide andsupport the delivery and positioning of the anchor implant. Properpositioning requires rotational control because of the C-shaped coaptivemargin of the native valve and the D-shaped annulus of native valve.Proper positioning of an anchor may also be facilitated by propercentering of the anchor structure prior to engagement and interface withthe native valve.

Thus, it is contemplated that a loop like structure can be employed toassist centering the system within the native annulus. Additionally, aloop with an axially directed bent V like structure can be used tofacilitate rotational orientation of the system if the limbs of the Vproject forward toward the commissures along the coaptive margin. Theexpression diameter (distance from center line) of the loops can both becontrolled with coaxial, but separate distal and proximal control of theloop structures; drawing the distal and proximal control points togetherexpands the loop structures.

A combination of a simple loop and V loop structure connected togethercan facilitate both rotational and centering of the structure and/oranchor. Accordingly, with reference to FIGS. 54-56, there is shown onecontemplated embodiment of an anchor guide tool 500. A distal end of thedevice forms a basket-like configuration defined by a first planar loop502 and a pair of generally V-shaped members 504. The basket-like distalend is attached to an elongate member 506 which has a length sufficientto be remotely controlled by an operator. The device can further beinserted through a tubular sheath 510 that acts to fold and compress thedistal end for advancement to the interventional site.

The struts defining the planar loop 502 and V-shaped member 504 can beconfigured to releasably engage an anchor frame (not shown). Proximaland distal connections between the struts and anchor structure can bearranged to accomplish variable express of the anchor within anatomy. Inuse (See FIGS. 57 and 58), the anchor guide device 500 is advancedacross a mitral valve, the planar loop 502 and V-shaped members 504being placed through the coaptation with lateral extremities configuredwithin the anterior and posterior commissures. Once so inserted, thevalve remains competent.

Turning specifically now to FIGS. 59-64, one particular approach toimplantation is presented. It is noted that delivery components of theanchor allow for tracking navigation through the various vasculature tothe right atrium, across the inter-atrial system, and facilitatingdirecting the anchor delivery toward the native mitral valve. FIG. 59illustrates an atrial, deflectable access catheter 600 in positionacross the atrial septum and within the left atrium. FIG. 60 illustratesa top view of the atrial access catheter in position across fossaovalis.

Referring now to FIGS. 61-64, there is shown components of oneembodiment of an anchor delivery system 700. FIG. 61 illustrates thedelivery system in its assembled form where various components arecoaxially arranged. An inner delivery catheter 702 is longitudinallytranslatable and insertable within a delivery sheath 704, which islongitudinally translatable and insertable within a deflectable sheath706. Each component defines a generally elongate profile having a lengthsufficient to extend from outside a patient's body, where a manipulationend is presented to an operator, to an interventional site within apatient's body, such as extending to the mitral valve through the venoussystem to the right atrium, across the atrial septum and into the leftatrium.

Focusing on the inner catheter 702, it includes a distal end 710configured to releasably engage an anchor assembly (not shown).Structure such as that depicted in FIGS. 54-56 can further be employedto so releasably engage portions of the anchor. As stated, otherstructure such as control wires can be utilized to effect desiredcontrol and releasable connections. For example, the hoops or loopspreviously described as forming part of the anchor can be used forreleasable connections to central wires (not shown). As such, the innercatheter is contemplated to include an inner elongate member 712extending from the distal end 710 through an inner catheter sheath 714to a proximal terminal end 716 of the device. The proximal terminal end716 can include a connection for manipulation by an operator so as tocause the inner elongate member 712 to slide within the inner cathetersheath 714. At a proximal end of the inner catheter sheath can beconfigured a W-connector 718. The W-connector includes a central opening719 for receiving the inner catheter elongate member 712 and a pair ofangled receivers 720 adapted to accept delivery control wires or otherstructure. Through the ability to longitudinally translate the innercatheter elongate member 712 with respect to the inner catheter sheath714, as well as through the use of various delivery control wires (notshown), desired manipulation of an anchor can be achieved.

The delivery sheath 704 (FIG. 63) is embodied in a tubular memberextending from a proximal terminal end 722 equipped with a connector 724having a hemostatic valve configured therein. Auxiliary access isprovided to the connector 724 via a side tube 725 terminal with aconventional touhy borst or other adapter. This access may be used forflushing, aspirating, infusing contrast, etc. A distal end 726 of thesheath 704 presents a generally circular opening sized and shaped toreceive an anchor assembly.

The deflectable sheath 706 (FIG. 62) also embodies an elongate tubularmember including a distal portion 730 and a proximal portion 732. Thetubular structure is of course large enough to receive the tubularstructure of the delivery sheath, the terminal end presenting agenerally circular opening. The proximal end 734 can be equipped with aconnector 736 also including a hemostatic valve and a side tube 737including a touhy borst or other adapter providing access to the valve.The proximal portion is also contemplated to include a control knob 740configured to accomplish through conventional methods the deflection ofthe distal portion 730 of the deflectable sheath 706. In this regard,the control knob can function to reel in or pay out wires extendingwithin the deflectable sheath and connected thereto at various points tocause a turning of the sheath to various degrees and angles, and at oneor multiple locations. The tubular body of the sheath is thuscontemplated to be axially flexible, as are the members defining theinner delivery catheter and delivery sheath. In this way, as thedeflectable sheath 706 is turned, or curved, the delivery catheter anddelivery sheath follow without kinking.

The deflectable sheath is contemplated to deflect into a curve adaptedfor entering a left atrium and secondarily, to be directed to the valve(back down at valve and then up out of plane as will be furtherdescribed below). Further, various combinations of catheter deflectionsare contemplated. There can be a single catheter with bi-directionalcapability, that is a primary bend at inter-atrial septum and a distalsecondary bend, as well as a proximal secondary bend (right atrial bendregion). Moreover, in a dual approach, there can be an inner secondarycurve ability. One key to the system is to prevent rotation of an innerdeflectable vs. an outer during secondary bending.

Expression of the anchor refers to its release from a collapsed stateinto an expanded shape for engagement and deployment into the nativevalve. Due to the limited working space to express the anchor above thenative valve, designs that allow for radial expansion during expressionprovide advantages. Additionally, component structures that providepreferential bending or folding points or planes during compression andthen expansion also provide advantages, such as ribbon like elementswithin the anchor design or strain relief eyelets/loops within theframe.

With reference to FIGS. 65-71, the technique of expression of an anchorcan be accomplished by advancement of the distal section of the anchor200 (shown as the frame 210 in the FIGS.) out of the delivery sheath 704until the distal tip (holding point) becomes proximate the native valvemitral valve plane. Note that curved deflectable catheter is not shownin these figures. The anchor 210 may first be only partially expressed,as in FIG. 67, by relative movement of the components of the innercatheter 702. The degree of expression (extent feet 214, 216 extend outfrom center point) can be controlled via the advance distance of innercoaxial pusher element of the inner assembly catheter. Next, the anchorand inner catheter are advanced across the mitral valve into theventricle. The anchor 210 can then be rotated into correct alignmentwith the commissures via the torqueable inner member (using previouslydetermined image plan as guidance). The anchor 210 may then be fullyexpressed in the ventricle, as shown in FIG. 69, then retracted toposition the feet into the gutter region under the valve leaflets.Release of the proximal anchor controls allows for the visor or apronelements of the anchor to provide supra-annular holding. Once the anchor210 is fully expressed, additional proximal controls can be used to makethe anchor feet 214, 216 co-planar with the native valve mitral valve,or the pre-formed shape of the feet may be suitable as a final deployedconfiguration for anchoring in the valve anatomy.

As shown in FIG. 71, recapture of the anchor assembly 210 via collapseof anchor via proximal and distal hold elongation with inversion of eachindividual foot is possible (here shown with use of optimal deflectablecatheter 600). In this way, the anchor can be repositioned as neededprior to final implantation.

To facilitate the correct placement of the valve with respect to theanchor, it may be desirable that the angular orientation of the valve beadjusted without substantial translation of the valve. This may beaccomplished by providing a valve delivery catheter 750 with anarticulating joint or gimbal 752 proximate a valve capsule 754 (SeeFIGS. 72-74). It has been found that such a joint allows the instantcenter of rotation of the valve capsule 754 to be close to the valvecapsule 754, thereby reducing the amount of translation of the valveduring deflection.

Considering now the trajectory of a valve delivery catheter assembly750, it can be seen that this joint 752 placement may also provide for aradius of curvature of less than 1 inch. The radius of curvature alsomay be less than about ½ inch, or, the radius of curvature may be lessthan 0.25 inch.

The flexible or articulating joint or gimbal 752 may be constructed byproviding a proximal section and a distal section of the catheterassembly 750 connected by a flexible connecting component. The flexibleconnecting component may be comprised of a flexible shaft 756. Theflexible shaft may be constructed from the following materials orelements: nitinol tubing, nitinol wire, braided polymer shaft, coilreinforced polymer shaft, elastomeric polymers, slotted metal tubing,etc. These elements may be combined to provide the desired columnstrength and flexural stiffness.

The joint or gimbal 752 may be provided with additional column strengthby providing a bearing surface 758 between the proximal and distalcomponents. This bearing surface may be spherical, cylindrical or othercurved surface. It is preferred that the surfaces have continuouscurvature to provide smooth operation in the desired direction. Forexample, a spherical bearing surface may enable articulation in a numberof different directions, while a cylindrical surface may limitdeflection to a plane perpendicular to the cylindrical surface. It canbe seen that If the bearing surface forms a complete sphere, the centerof rotation of the proximal and distal components will be at the centerof the sphere. In some cases it may be desirable for the length of thejoint to be smaller than the diameter of the spherical bearing surfaces.In this case, the bearing surface can be truncated such as in the caseof a spherical cap or dome. This enables both the length and diameter ofthe joint to be reduced.

The joint or gimbal 752 may further include a center lumen or guidewirelumen 760. In this case it is desirable that the curvature of the centerlumen be minimized to improve guide wire movement and prevent kinking.It can be seen that shaft curvature is minimized for given angulardeflection and arc length when the curvature is constant along the arc.It has been found that for the joint design of FIG. 73, this can beaccomplished by allowing the instant center of rotation of the proximaland/or distal components to change as the joint is deflected. Incontrast, the bearing surfaces 761 of the joint shown in FIG. 74constrain the location of the center of rotation. In the case ofspherical or cylindrical bearing surfaces, it has been found that thismay cause the center lumen to assume an undesirable non-uniformcurvature. In this case it may be advantageous not to affix the centerlumen to the bearing surfaces but to allow them to move to permit a moregradual curvature. Alternatively, the free length of the center lumenand the curvature of the bearing surfaces may be chosen to reduce thecurvature of the center lumen.

In some cases, it may be desirable for the joint to deflect orarticulate freely under loads applied to the catheter or valve capsule.In other cases, it may be advantageous to actuate the deflection beexternal means. In these embodiments, deflection may be accomplished bymeans of actuators connecting the proximal and distal components at atleast one location away from the centerline of the joint. Theseactuators may be comprised of wires, tubes, yarns, cables, or threads,herein called wires 762 (See FIGS. 75-76). In one embodiment, tensionapplied to a single wire causes deflection in that direction. In anotherembodiment, two wires acting in opposition to each other causedeflection and straightening in one direction in a plane. In still afurther embodiment, three or more non-co planar wires enable deflectionin a plurality of planes or directions. Moreover, a plurality ofnon-coplanar wires enables deflection in substantially any direction. Inyet another embodiment, a plurality of wires acting in both a tensileand compressive direction provides both deflection and axial compressionresistance.

Control of the actuating wires can be accomplished by means of knobs andlevers. It has been found that the effective length of actuators passingthrough a catheter may be affected by deflection of the catheter,resulting in potentially undesirable actuation effects. This effect canbe mitigated by providing actuator guide lumens with proximal and distalends, said ends fixed relative to proximal and distal actuatoreffectors. These actuator guide lumens are allowed to move within thecatheter shaft in regions between the proximal and distal ends so as tocompensate for flexure of the catheter. In one embodiment, the actuationeffectors are constructed so that deflection of an actuator on one endof the catheter results in an opposite deflection at the other end ofsaid catheter. The magnitudes of said deflections may be scaled tocompensate for stretching or deformation of catheter components underactuation stresses. It can be seen that multiple bends by be controlledby attaching the actuators in series with each other. The controlmechanism may be locked in place by tightening a collar against theproximal bearing surface.

In order to maintain control of the valve during deployment it may bedesirable to provide a rigid coupling segment across the interfacebetween valve and catheter at the proximal end of the valve deliverycapsule. It is further advantageous to minimize the overall length ofthe stiff section of the valve capsule. To this end, the sheath isconstructed as a telescoping assembly where the comparatively stiffproximal section of the valve capsule bridging the proximal valveinterface is kept short and a landing zone is provided for thetelescoping valve segments. In one embodiment, the telescoping valvesegments are provided with flanges that interact with each other toensure that segments pull back in the proper manner. In a preferredembodiment, the actuator wires attach to the distal capsule 754. Thedistal capsule under influence of the actuator wires slides back overthe proximal capsule. The distal capsule is provided with a flange thatengages a corresponding flange on the proximal capsule, thereby causingin to retract in turn. It can be seen that this can be extended to anynumber of sections in order to further shorten the length of eachindividual section and the required length of landing zone. In someembodiments, some of the capsule sections are rigid, where others areflexible. Flexible capsule segments may be configured so as to pass overthe landing zone and follow the curve of the catheter. In someembodiments, flanges are provided to limit the extension of the capsulesegments. This facilitates loading of the valve into the capsule andprevents inadvertent detachment of the capsule.

In another embodiment, the capsule 770 is constructed in a helicalmanner (See FIG. 77), with substantially cylindrical sections at theproximal and distal end of the capsule to facilitate loading, actuationand attachment. In some of these embodiments, the helical sleeve 772 isprovided with a flange. In some embodiments, the helical sleeve elementsare substantially parallel to the axis 776 of the catheter but form astepped conical structure of decreasing diameter. In other embodiments,the helical sleeve 772 elements are inclined with respect to thecatheter axis 776 but maintain a substantially constant diameter alongthe length of the capsule 770.

It has been found that for controlled valve deployment it isadvantageous for the valve capsule 780 to resist deformation in radial,axial and circumferential directions but to retain sufficientflexibility to follow the curve of the catheter during capsule pullbackand to provide a lubricious inner surface to reduce frictionalresistance during valve deployment (See FIGS. 78A-F). A structurecomprising a plurality of concentric layers has been developed thatprovides these properties. In one embodiment, an inner layer ofsubstantially axially oriented strips 782 of PTFE is surrounded with anouter layer of circumferentially reinforced elastomeric tubing 784. Theaxial strips 782 are able to move with respect to each other to reducepeak strain. The axial strips 782 are constrained from expanding by theouter layer of tubing 784. The elastomeric material properties providesufficient flexibility to prevent kinking and the circumferentialreinforcement resists expansion. The reinforcement material may be inthe form of a coil or braid or rings. Materials may include stainlesssteel, elgiloy mp35N Tungsten, Kevlar, aramid, Liquid crystal polymer,glass or ceramic fibers, filaments or yarn. In some embodiments theaxial strips maybe bent inwards at the distal end to provide a smoothertransition.

In some cases, after complete or partial deployment of the valve it isdesired to remove or reposition the valve by retracting in completely orpartially into a catheter. Such retraction requires overcomingsubstantial outward expansion force of the valve. It has been found thatthis is facilitated by providing a gradual tapered transition to guidethe expanded valve into a smaller retrieval tube (See FIG. 79). In someembodiments, this transition is provided by an expandable funnelcomponent 790. In some embodiments, this device is integral with thedelivery catheter. In other embodiments, the funnel 790 may be part of aseparate retrieval device. In still other embodiments, the funnel 790may be part of a deflectable sheath component. In all cases, it iscontemplated that the funnel can exhibit high axial and radial stiffnessin its expanded configuration, while collapsing to a comparativelysmaller diameter for delivery and retrieval.

In one embodiment, the expandable funnel 790 is comprised of a pluralityof petal-like structures 792. These structures are configured to slideover each other to expand from a generally cylindrical configuration toa generally conical configuration. The individual petals 792 may bekeyed to each other or constrained by another component to limit radialexpansion. In some embodiments, slots are provided at the transitionfrom a cylindrical to a conical geometry to reduce stress. The petalmaterials may be materials such as polyimide, Nitinol, high densitypolyethylene, Teflon or FEP. Moreover, they may be reinforced or theymay be constrained on the outside be a braid. The funnel 790 may bereleased by continued pullback or the valve capsule or it may beadvanced out of the valve delivery catheter after valve delivery.

In another embodiment, the funnel 790 is formed by a braid that isinvaginated onto itself forming a conical distal chamber. The dimensionsof such a braid are selected to provide both axial and radial stiffnessin the expanded configuration. The braid angle and pic count maybevaried along the length of the braid.

Next addressed are general requirements for delivering a replacementmitral valve via a trans-septal approach, into a previously placedanchor. It is desirable that the valve be collapsed/compressed andencapsulated in some manner to navigate the venous system to the rightatrium and to cross the inter-atrial septum and engage the native valveand the anchor ring in the disclosed embodiment. Also, given therelative stiffness of the collapsed valve assembly in this region, theremay be a need for a flexible or possibly articulating segment proximaland possibly distal of the encapsulated valve region of the deliverysystem to aid with tracking. Further, the delivery system should be ableto navigate a primary curve in the right atrium and trans-septal regionof the anatomy. The system can then be able to navigate a secondarycurve from the septum back toward the mitral valve, which may be out ofplane relative the primary curve. The encapsulated valve can then alsobe able to be controllably expressed out of the catheter. In general,this can be accomplished via an advancement of the valve out of thecatheter or via a pullback of an encapsulating sheath. The formerrequires significant adjustment and anticipation of final valve positionas it is expressed. Unsheathing allows the valve to be in relative axialposition prior to expression into the anchor structure. It may also bedesirable during valve delivery to be able to reposition prior to fullexpression and deployment, primarily axially and to recapture orretrieval of the valve for removal prior to and after full expressionand deployment. Moreover, it may be desirable for the delivery system tohave temporary or releasable connections or holding points to controlposition as the valve begins to become loaded, as well as enableretrieval. Imaging visibility on fluoro and echo to facilitate alignmentand positioning relative to native valve and the anchor of the disclosedembodiment is also contemplated. The alignment and positioning of thesystem includes axial position, rotational orientation, planar x-yposition relative to native valve plane, and the axial vector relativeto the perpendicular vector of the native valve plane.

It is to be noted that the creation of a flexible or articulating regioncan be accomplished via flexible shaft materials and construction andcan be improved or augmented with deflectable catheters. Controlleddeflection can occur in multiple locations along the catheter shaft andcan be done to accomplish deflection that occurs in different planes. Asystem with multiple coaxial catheters for a valve delivery system canhave one catheter that deflects or multiple catheters that deflect tocreate the proper compound vectoring to the mitral valve in atrans-septal configuration. Specifically, an outer catheter may be usedto create the primary curve described with an inner catheter or shaftassembly utilized to create the secondary curve.

With this in mind, we turn to FIGS. 80-83A which depict components ofone particular approach to a valve delivery catheter system 800. Thedelivery catheter 800 is generally elongate and tubular. A distal endportion 802 includes a valve capsule 804 sized and shaped to receive aradially compressed valve assembly. A marker 808 can be configured atthe distal end to provide a visual aid when using remote viewingtechniques. A proximal end portion 806 terminates in a hub 808 providingaccess for an actuator 810 and other structure such as control wires orthe like. The actuator 810 itself can include a handle 812 and a lever814 for controllable manipulation of a control member 820. A mid-section824 of the collection system 800 is characterized by corrugatedsections.

With reference to FIGS. 84-89, there are shown various angles which theanchor delivery catheter and valve delivery catheter 800 are expected toassure and traverse through anatomy. It has been found that such sharpangles can cause conventional tubular structures to buckle and collapse,thus limiting an ability to reach a target interventional site withinanatomy like the heart H. The corrugated section 826 of the catheter 800provides structure which can bend or curve without suffering frombuckling or collapse. Moreover, knowing the anatomy leading to a mitralvalve lends itself to providing a catheter prepared to deflect tonavigate known anatomical structures. For example, the catheter 800 canbe configured to include multiple deflection points. One deflectionpoint 830 can be provided so that passage through the right atrium orIVC is possible (FIG. 78). Another deflection point 832 can permitpassage through fossa ovalis (FIG. 79). In an alternative approach (SeeFIGS. 88-89), a deflection point 834 can direct the catheter from theleft atrium to the mitral valve and another deflection point 836 canaccomplish passage through the fossa ovalis. Other deflection points canalso of course be incorporated to traverse other anatomy.

Returning to FIG. 81, one can appreciate control of axial bending of thevalve delivery catheter 800. One or more control wires can be attachedat a distal end to interior walls. Withdrawal of or otherwise placing atension on the control wires from a proximal end of the wire will causethe portion of the corrugated section 826 to be withdrawn to express thevalve. Further controls are also contemplated to permit certain patternsor certain ordering of degrees of bending or turning to thereby relievepossible reliance upon remote imaging. Regarding FIG. 75B, prior todeployment, the capsule 804 can be axially positioned and aligned withthe waist section 301 centered with the anchor ring 210. While in thepreferred imaging plane, the delivery catheter can also be positionedper the methods described in FIGS. 53B-53E.

Once the distal portion 802 of the valve delivery catheter system 800 isplaced as desired within or proximate an anchor assembly using one orboth of remote visualization and planned or adaptive articulation of thecatheter, steps can be taken to eject a valve assembly from the valvecapsule 804. To accomplish this, various approaches can be taken basedupon a number of contemplated configurations of catheter shaftconstruction to enable releasable encapsulation of the replacementvalve. In one approach, dual catheter construction with outer pullbackis provided. Thus, a partial sheath with a pull system internalized oninner catheter can be utilized, or alternatively the delivery cathetercan be equipped with a complete sheath along length. Moreover, thecatheter can include a distal capsule pullback with collapse of aninside of an outer or a dual catheter with inner sheath pullback. Distaland proximal sheaths are also contemplated where a distal sheath isadvanced off and a proximal is pulled off. Finally, also contemplated isa single sheath catheter pulled back off of a valve (inner assemblyholds valve).

In any event, in one particular approach, a distal end of the catheter802 can include two control features. A terminal end ball 858 can beprovided to function both to retain the valve within the capsule 810 aswell as present an atraumatic surface for navigating anatomy. Positionedproximally along a retainer bar 859 a length sufficient to accept avalve implant is a retaining surface 860. Thus, withdrawing the capsule804 results in the ball 858 and retaining surface 860 maintain thelongitudinal position of the valve. As the capsule is withdrawn, thevalve returns to its expanded state and into engagement with the anchor.The delivery catheter is then withdrawn from the intervention site tothereby replace a mitral valve.

Further modifications and alternative embodiments will be apparent tothose of ordinary skill in the art in view of the disclosure herein. Forexample, the systems and the methods may include additional componentsor steps that were omitted from the diagrams and description for clarityof operation. Moreover, those of ordinary skill in the art willappreciate that aspects and/or features disclosed with respect to oneembodiment in some cases may be incorporated in other embodiments evenif not specifically described with respect to such other embodiments. Itis to be understood that the various embodiments shown and describedherein are to be taken as exemplary, including dimensions of variouscomponents, and as such various sizes outside of identified ranges arealso contemplated. Elements and materials, and arrangements of thoseelements and materials, may be substituted for those illustrated anddescribed herein, parts and processes may be reversed, and certainfeatures of the present teachings may be utilized independently, all aswould be apparent to one skilled in the art after having the benefit ofthe description herein. Changes may be made in the elements describedherein without departing from the spirit and scope of the presentteachings and following claims. Accordingly, this description is to beconstrued as illustrative only and is for the purpose of enabling thoseskilled in the art the general manner of carrying out the presentteachings. It is to be understood that the particular examples andembodiments set forth herein are nonlimiting, and modifications tostructure, dimensions, materials, and methodologies may be made withoutdeparting from the scope of the present teachings. Other embodiments inaccordance with the present disclosure will be apparent to those skilledin the art from consideration of the specification and practice of theinvention disclosed herein. It is intended that the specification andexamples be considered as exemplary only, with a true scope and spiritbeing indicated by the following claims.

Thus, it will be apparent from the foregoing that, while particularforms of the invention have been illustrated and described, variousmodifications can be made without parting from the spirit and scope ofthe invention.

We claim:
 1. A mitral valve replacement system for a heart, the mitralvalve including commissural clefts, an anterior leaflet, a posteriorleaflet, an annulus and a sub-annular gutter, comprising: an anchorassembly configured for placement within the heart, the anchor assemblyincluding a retention structure and a plurality of projections, whereinthe anchor assembly is movable between a compressed configuration and anexpanded configuration, in which the retention structure is configuredfor placement at or proximate the mitral valve annulus, while theplurality of projections are placed into contact with the sub-annulargutter, and an artificial valve comprising an expandable frame having agenerally D-shaped outer peripheral region configured for engagementwithin the retention structure of the anchor assembly, and a circularvalve orifice located radially inward from the generally D-shaped outerperipheral region and carrying valve leaflets directly attached to thecircular valve orifice, wherein the expandable frame of the artificialvalve is expandable from a collapsed configuration, while the anchorassembly remains in the expanded configuration, to a deployedconfiguration to selectively contact and mate with the retentionstructure of the anchor assembly; wherein the anchor assembly leaves theleaflets of the mitral valve unaffected and the anchor assembly does notinterrupt leaflet, chordae, or native valve function of the mitral valveprior to placement of the artificial valve.
 2. The system of claim 1,wherein the anchor assembly is sized and shaped to be implanted withoutreshaping the annulus.
 3. The system of claim 1, wherein the pluralityof projections include a curved portion.
 4. The system of claim 1,wherein the anchor assembly comprises a first nickel titanium alloy wireconstruction that is movable between the compressed configuration andthe expanded configuration, and wherein the expandable frame of theartificial valve comprises a second nickel titanium alloy wireconstruction that is expandable independently from the first nickeltitanium alloy wire construction of the anchor assembly.
 5. The systemof claim 1, wherein the artificial valve is configured to seal againstnatural tissue.
 6. The system of claim 1, wherein the anchor assemblyincludes a supra-annular holding structure.
 7. The system of claim 6,wherein the supra-annular holding structure comprises at least one of anapron and a visor.
 8. The system of claim 1, further comprisingproviding a sealing element between the anchor assembly and theartificial valve, wherein the sealing element is configured to promotetissue ingrowth.
 9. The system of claim 1, wherein the plurality ofprojections of the anchor assembly are each a sub-annular projectionspositioned lower than the retention structure when the artificial valveis deployed to mate with the retention structure of the anchor assembly,and the anchor assembly further includes a generally central hubpositioned lower than the sub-annular projections and positionedradially inward from the retention structure and the sub-annularprojections when the artificial valve is deployed to mate with theretention structure of the anchor assembly.
 10. A mitral valvereplacement system for a heart having an inflow end and an outflow end,the mitral valve including commissural clefts, an anterior leaflet, aposterior leaflet, an annulus and a sub-annular gutter, comprising: ananchor assembly configured for placement within the heart, the anchorassembly including a first expandable frame movable between a compressedconfiguration and an expanded configuration, a retention structurecloser to the inflow end than the outflow end and a plurality ofsub-annular projections, two of the plurality of sub-annular projectionsin the expanded configuration being configured to be in contact with thesub-annular gutter proximate the commissural cleft and another two ofthe plurality of sub-annular projections in the expanded configurationbeing configured to be in contact with the sub-annular gutter behind theposterior leaflet in the sub-annular gutter, wherein in the expandedconfiguration each of the plurality of sub-annular projections has oneof its two ends attached to a portion of the anchor assembly that isradially inward of and below the retention structure and closer to theoutflow end than the inflow end; and an artificial valve comprising: asecond expandable frame and valve leaflets attached to the secondexpandable frame, wherein the second expandable frame of the artificialvalve is expandable from a collapsed configuration, while the anchorassembly remains in the expanded configuration, to a deployedconfiguration to selectively contact and mate with the retentionstructure of the anchor assembly; wherein the anchor assembly leaves theleaflets of the mitral valve unaffected and the anchor assembly does notinterrupt leaflet, chordae, or native valve function of the mitral valveprior to placement of the artificial valve.
 11. The system of claim 10,wherein the anchor assembly is sized and shaped to be implanted withoutreshaping the annulus.
 12. The system of claim 10, wherein theartificial valve includes a sealing structure configured to engagenatural tissue.
 13. The system of claim 10, wherein the first expandableframe of the anchor assembly comprises a first nickel titanium alloywire construction that is movable between the compressed configurationand the expanded configuration, and wherein the second expandable frameof the artificial valve comprises a second nickel titanium alloy wireconstruction that is expandable independently from the first expandableframe of the anchoring assembly.
 14. The system of claim 10, the anchorassembly further comprising a supra-annular holding structure.
 15. Thesystem of claim 14, wherein the supra-annular holding structurecomprises at least one of an apron and a visor.
 16. The system of claim10, wherein at least one projection of the plurality of sub-annularprojections includes a curved portion.
 17. The system of claim 10,further comprising providing a sealing element between the anchorassembly and the artificial valve, wherein the sealing element isconfigured to promote tissue ingrowth.
 18. The system of claim 10,wherein the plurality of sub-annular projections of the anchor assemblyare positioned lower than the retention structure in the expandedconfiguration of the anchor assembly, and the anchor assembly furtherincludes a generally central hub positioned lower than the plurality ofsub-annular projections and positioned radially inward from theretention structure and the plurality of sub-annular projections whilethe anchor assembly is in the expanded configuration.
 19. The system ofclaim 10, wherein the plurality of sub-annular projections consists offour sub-annular projections, wherein first and second sub-annularprojections of the four sub-annular projections are positioned lowerthan the retention structure to anchor sub-annularly proximate thecommissural cleft, and wherein third and fourth sub-annular projectionsof the four sub-annular projections being positioned lower than theretention structure to anchor sub-annularly behind the posterior leafletin the sub-annular gutter.
 20. A mitral valve replacement system for aheart, the mitral valve including commissural clefts, an anteriorleaflet, a posterior leaflet, an annulus and a sub-annular gutter,comprising: an anchor assembly configured for placement within theheart; an artificial valve configured to contact and mate with aretention structure of the anchor assembly; the anchor assembly beingmovable to an anchoring configuration in which the artificial valve isdeployed within the anchor assembly, the anchor assembly in theanchoring configuration includes: the retention structure, a pluralityof sub-annular projections positioned lower than the retentionstructure, and a generally central hub positioned entirely below theretention structure, positioned entirely below the plurality ofsub-annular projections, and positioned radially inward from theretention structure and the plurality of sub annular-projections, atleast one of the plurality of sub-annular projections being configuredto engage with the sub-annular gutter; and wherein the anchor assemblyleaves the leaflets of the mitral valve unaffected and the anchorassembly does not interrupt leaflet, chordae, or native valve functionof the mitral valve, while said at least one of the plurality ofsub-annular projections is configured to engage with the sub-annulargutter.
 21. The system of claim 20, wherein the anchor assembly is sizedand shaped to be implanted without reshaping the annulus.
 22. The systemof claim 20, wherein at least one projection of the plurality ofsub-annular projections has a curved portion.
 23. The system of claim20, wherein the anchor assembly is movable between a compressedconfiguration and an expanded configuration.
 24. The system of claim 20,wherein the artificial valve is configured to seal against naturaltissue.
 25. The system of claim 20, wherein the anchor assembly includesa supra-annular holding structure.
 26. The system of claim 25, whereinthe supra-annular holding structure comprises at least one of an apronand a visor.
 27. The system of claim 20, wherein the artificial valvecomprises: an expandable frame that defines both a circular valveorifice with valve leaflets directly attached thereto and a generallyD-shaped outer peripheral region configured for engagement with theretention structure of the anchor assembly, the circular valve orificebeing located radially inward from the generally D-shaped outerperipheral region.
 28. The system of claim 27, wherein the anchorassembly is movable between a compressed configuration and an expandedconfiguration, wherein the expandable frame of the artificial valve isexpandable from a collapsed configuration, while the anchor assemblyremains in the expanded configuration, to a deployed configuration toselectively engage with the retention structure of the anchor assembly.